Su-ngai Kolok (Thai: สุไหงโก-ลก, pronounced [sū.ŋǎj kōː.lók]) is a district (amphoe) of Narathiwat province, southern Thailand.

The minor district (king amphoe) was created on 2 January 1948, consisting of the three tambons: Su-ngai Kolok, Puyo, and Pase Mat from Su-ngai Padi district and Muno from Tak Bai district.

[2] Neighboring districts are (from the southwest clockwise) Waeng, Su-ngai Padi and Tak Bai.

The district is divided into four sub-districts (tambons), which are further subdivided into 19 villages (mubans).

Su-ngai Kolok itself has town (thesaban mueang) status and covers most parts of the same-named tambon.